The response of diel extracellular α and β-glucosidase activity to in situ dissolved carbohydrates was explored in coastal marine waters. The hypothesis being tested was to determine whether natural substrate could regulate enzyme activity. Relative enzyme activity was determined using artificial 4-methylumbelliferone (MUF) substrate derivatives at low substrate concentrations (300 nM). Disssolved carbohydrate concentrations were measured using the 3-methyl-2-benzothlazolinone hydrazone hydrochloride (MBTH) method: a spectrophotometric determination of monosaccharide concentrations. Six studies were conducted and p-glucosidase activity (BOA) was found to be positively correlated with dissolved polysaccharide concentrations (PCHO) in two studies which suggests that PCHO can potentially regulate BOA. A significant inverse correlation (Spearman) between dissolved monosaccharides (MCHO) and β-glucosidase activity was found in one study suggesting that MCHO was capable of repressing and/or inhibiting the activity of β-glucosidase under some conditions. Three significant positive relationships were found between α-glucosidase (AOA) and BOA suggesting that there was a tight coupling between substrate release and hydrolysis. No obvious relationships were found between hydrolytic enzymes and dissolved carbohydrates in three diel studies. This may have been due to uncontrollable factors such as nutrient limitation, grazing and the inability to distinguish between α- and β-glucans. Combined data for PCHO and BOA showed an inverse relationship suggesting that high levels of naturally occurring PCHO may compete with MUF-β-glucans for β-glucosidase active sites causing a lower rate of MUF-β-glucan hydrolysis.

The distribution and abundance of ghost crab (Ocypode quadrata) burrows on Hillsboro Beach, Florida, and their relationship to, and effect on sea turtle nests were documented at three control sites and three experimental sites from April 1994 through October 1994. The three experimental sites were located immediately to the east of three open beach sea turtle hatcheries and the control sites were established on nearby open beaches. The purpose of this work was 1) to determine if a larger population of O. quadrata occurred near sea turtle hatcheries than elsewhere along Hillsboro Beach and 2) to assess possible impacts of O. quadrata infestation on turtle hatchling emergence success. O. quadrata abundance was not significantly different at the experimental and control areas. Within the hatcheries, ghost crabs did invade sea turtle nests both before and after hatching. The emergence success of nests invaded prior to hatching was significantly lower than for non-invaded nests. Ghost crab predation appeared to significantly increase the percentages of unhatched eggs, but did not significantly change the percentages of pipped eggs or dead-in-nest hatchlings, relative to uninvaded nests.

The yellow stingray, Urolophus jamaicensis, is a small, common western Atlantic fish. Although it is abundant in coastal waters from North Carolina to Brazil, very little work has been done on the anatomy of this animal. It has been previously demonstrated in two Pacific congeners that there are several structural differences in urolophid gill vasculature from other elasmobranchs. The gill vasculature of U. jamaicensis was examined in order to investigate the hypothesis that these structural differences may be common to the genus Urolophus. Gross examination of preserved gills using light microscopy confirms that the basic structure of U. jamaicensis' gill arches is similar to that reported from other elasmobranchs. However, scanning electron microscopic examination of Mercox methylmethacrylate casts of the fine gill vasculature confirms several structures not reported in non-urolophid elasmobranchs. The differences include; 1) absence of a septal corpus cavernosum; 2) the presence of a vessel which connects the afferent filament arteries near the tip of each filament; and 3) a vessel, possibly an extension of the afferent filament artery, that runs along the top of the filament corpus cavernosum possibly connecting the afferent and efferent filament arteries at the tip of some filaments. The fine vascular structures identified in U. jamaicensis are very similar to those previously described in U. paucimaculatus and U. mucosus in the western Pacific.

A study was conducted in the Gulf of Mexico to investigate the spatial and temporal variability in secondary production of western Florida waters. The area of interest was divided into four regions representing shelf and oceanic environments of the northern and southern Gulf waters. Physical parameters measured at the same locations in each region were examined in the spring (March 1992) and fall (October 1992). Secondary production of copepods was estimated indirectly from preserved plankton samples. Six copepod species chosen for this study were: Centropages velifurcatus, Eucalanus monachus, Rhincalanus cornutus, Temora stylifera, Temora turbinata and Undinula vulgaris. Adult (C6) female copepods were stained with celestine blue to examine their gonads to determine their level of oocyte maturation. A potential egg production index (PEPI) was determined for each female using the number of mature eggs multiplied by the state of gonad maturity, as determined by Runge (1985). The average PEPI was calculated for each species in both spring and fall in each of the four shelf regions. Centropages velifurcatus, Temora stylifera, and Undinula vulgaris appeared to be in an advanced state of reproductive readiness at all locations at which they were sampled. The remaining three species, Eucalanus monachus, Rhincalanus cornutus, and Temora turbinata, were immature. A regression analysis of physical parameters showed a significant correlation (P<0.05) with fluorescence as an indicator of potential food. The results of a MANOVA for season, species, and location against PEPI showed U. vulgaris as the most productive and R. cornutus as the least. Mean PEPI differed significantly between spring and fall for all species. Southern oceanic location C was the least productive of the four regions sampled (P<0.05). The remaining three regions exhibited no significant differences in their average potential egg production indexes.

The best available biological information for the silky shark, Carcharhinus falciformis, was used to produce a demographic analysis for the silky shark population off the southeastern U.S. Monte Carlo simulation was used to vary natural mortality (M), fecundity (mx), age-at-maturity (tmat) and longevity (tmax) to account for some of the uncertainty in these vital rates. Demographic analyses were run 1000 times to allow estimation of 95% confidence intervals. Under the scenario of natural mortality only, results indicated the silky shark population would grow at a rate of 4.5 %/year (R0 = 2.038, G = 16.223, and r = 0.044). Adding the latest available fishing mortality estimate (F) for large coastal sharks resulted in a population decreasing at a rate of 4.8%/year. Finally, to incorporate the hypothetical effect of gear selectivity on fishing mortality, length frequencies for silky sharks caught on longlines off the southeastern U.S. were used to estimate gear selection at various ages. Demographic analyses that consider hypothetical gear selection, when compared to analyses using constant across-age mortality models, suggest that gear selectivity and the resulting fishing mortality-at-age may be an important influence on demographic model output, and should be considered where possible when using demographic analyses as management tools.

Several genera in the comatulid family Mariametridae are currently ambiguously distinguished on the basis of variations in length and robustness of oral pinnules. Previous descriptions have suggested that at least the genera Stephanometra and Lamprometra are imperfectly distinguishable. A detailed re-examination of morphology coupled with principal component analyses of morphometric data and cladistic analyses provide support for a monophyletic Stephanometra distinct from Lamprometra. A preliminary morphological analysis suggests that Dichrometra and Liparometra should be synonymized with Lamprometra. The six currently recognized species of Stephanometra uniquely share at least one pair of oral pinnules characterized by enlarged size, reduced ambulacral groove and flat, almost featureless articular facets that together produce a large, stiff, spinelike pinnule. Additional features distinguishing Lamprometra from Stephanometra include oral pinnular proportions, distribution of cirri and the nature of the adambulacral margin along the brachitaxes and arm bases. Within Stephanometra, two groups of species are currently recognized. Those of the first group, S. echinus and S. tenuipinna, have long sharp aboral spines on distal cirrals and a spinelike fIrst pinnule. Those in the second group, S. spinipinna, S. indica, S. spicata and S. oxyacantha, lack aboral cirral spines and are differentiated by oral pinnule features. The latter three have a slender, flexible first pinnule and are distinguished by the number of enlarged spinelike pinnules that follow. In S. spinipinna, the first pinnule is also spinelike. Twenty percent of the specimens examined in the indica-spicata-oxyacantha series are intermediates that cannot be satisfactorily assigned to species based on current diagnoses. Cladistic analyses suggest that these three form a continuum and should be synonymized (under S. indica), that S. spinipinna should be assigued to S. indica, and that S. echinus and S. tenuipinna are synonymous (with S. tenuipinna the senior name). Likewise principal component analysis illustrates distinct groupings for these two species.

The crinoid family Comasteridae has undergone several revisions based on morphological characters. None, however, have employed DNA sequence data to generate a phylogenetic hypothesis for the group. To elucidate both monophyletic clades and generic interrelationships, DNA was obtained from 32 taxa, and 655 aligned base positions from near the 3' terminus of the mitochondrial 16S rDNA gene were sequenced. The results of analyses by maximum parsimony, neighbor-joining, and maximum likelihood methods support the majority of the current morphologically defined generic designations, though one genus emerges as paraphyletic and another as polyphyletic. Intergeneric relationships are less clear though strong support of several sister-clade relationships is evident including Comatella/Alloeocomatelia and Comanthus (in part)/Clarkcomanthus. Subfamilial designations are moderately to strongly supported in the Comanthinae but weakly supported elsewhere. This initial assessment of phylogenetic relationships within the family poses a number of additional questions and directions for future research. It will serve as the launching point for future systematic research both within the family Comasteridae and for comatulid crinoids in general.

Ergosterol analysis techniques are relatively new methods for measuring fungal biomass. Ergosterol is a sterol found in the plasma membrane of eumycotic fungal cells. It is unique to higher filamentous fungi and is not found in the plasma membrane of other eukaryotes. Thus, quantifying fungal biomass can be achieved by isolating ergosterol. The purpose of this study was to measure seasonal changes in fungal biomass in intertidal and submerged wood substrates in a South Florida mangrove ecosystem by ergosterol analysis. In addition, fungal species were identified within a South Florida mangrove forest along the Loxahatchee River. Mesh bags containing four different substrates were placed along Whiskey Creek in John U. Lloyd State Park, Florida The four substrates were Red Oak wood, Quercus rubra, Yellow Pine wood, Pinus leiophylla, Red Mangrove wood, Rhizophora mangle, and R. mangle leaves. Mesh bags were placed in the intertidal zone in January, March, May, and September of 2002 and ergosterol levels were measured each month for the four different substrates. Another set of the four different substrates was completely submerged in August 2002, and ergosterol measurements were recorded monthly. Seasonally, it was found that ergosterol levels were higher in the late spring and early summer months. This might be due to the higher water levels in the winter and fall, which increased competition for the available substrates. Ergosterol levels were noticeably lower in the submerged Red Mangrove leaves as compared to the intertidal Red Mangrove leaves. Newell (1997) found similar results and concluded that leaves in the upper intertidal zone that are exposed to periodic desiccation might favor eumycotic fungal growing conditions, whereas Oomycetes, a mycelial protist, might out-compete higher filamentous fungi in submerged leaves. The marine mangrove fungi found along the Loxahatchee River were similar to the mangrove species reported in previous tropical and subtropical studies. The majority (73%) of species was Ascomycetes. The dominant species were Marinosphaera mangrovei, Hypoxylon oceanicum, Cytospora rhizophorae, and Caryosporella rhizophorae. These species are commonly found on Rhizophora mangle. Noticeable trends in seasonal fungal distributions, in addition to differences in fungal biomass between submerged and intertidal mangrove leaves, were evident during the course of this study. Fungi have been shown to play an important role in nutrient recycling within mangrove ecosystems. This study demonstrated that ergosterol methods are appropriate for the study of mangrove fungi. Future studies will likely provide greater insights into the activities of filamentous marine fungi in estuarine and near-shore ecosystems.

The feeding mechanism of two species of the tanaidacean family Kalliapseudidae: Kalliapseudes sp. A McSweeny 1968, and Psammokalliapseudes granulosus Brum 1973, was elucidated by comparing gut contents, mouthpart morphology, and feeding behavior. This was achieved by using a combination of light microscopy, scanning electron microscopy, and observation of living organisms. Morphological differences of the mouthparts are directly associated with the feeding mechanism. Kalliapseudes sp. A filter feeds and possesses plumose setae on the chelipeds, maxillipeds, and maxillae. When building their tubes, P. granulosus scrapes detritus off sand grains by using the comb setae on the maxillae. They suspension feed when settled in their tubes by trapping detritus on the antennular setae. Both species feed primarily on detritus. Diatoms were the second most abundant food item in the foregut of Kalliapseudes sp. A. Comparisons of foregut morphology were made that attempted to relate structure and function. Foreguts were nearly identical, which could be attributed to the utilization of a common food source. The male of P. granulosus is described and illustrated for the first time. Two forms of copulatory males differ with respect to cheliped shape and pereopod setation.

The growth and survivorship of two species of scleractinian coral transplants, Meandrina meandrites and Montastrea cavernosa, were investigated. Identically sized replicate transplants were obtained from the second reef, off Dania Beach, using a hydraulic drill fitted with a 4” core barrel. The transplants were fixed to Reef Ball™ substrates using an adhesive marine epoxy. Drill holes in the donor corals (core holes) were filled with concrete plugs to prevent the detrimental effects of bioeroders. Control corals, of comparable size to both the donor colonies and the transplant corals, were selected for comparison. The transplant corals, donor corals, and controls on the natural reef were monitored for growth and survivorship. The core holes were monitored for tissue regrowth over the surface of the concrete plug, in order to assess the effectiveness of the plugging process. Growth during the transplantation project was defined as an increase in surface area or radius, and was monitored on a quarterly basis using photographic techniques. SigmaScan© Pro4 image analysis software (Jandel Scientific Corporation) was used for the analysis of the photographic data. The following main hypothesis was tested: species-specific differences will occur in the responses of coral colonies to drilling and transplantation. Additional sub-hypotheses were tested, including: 1) a change in surface area and/ or radius in the experimental corals and the control corals will take place, 2) the survivorship of the experimental corals and their control corals will be similar, 3) a change in surface area and/ or radius of the tissue surrounding the core holes will take place. Meandrina meandrites transplants exhibited a substantial amount of mortality and displayed significantly less growth (both in surface area and radius change) than M. cavernosa transplants, and the M. meandrites controls. Montastrea cavernosa transplants experienced significantly more growth than their same species controls. All donor corals that experienced drill damage (separate from the drill holes) were able to regenerate the injured tissue in a period of less than three months. No significant difference was found for the change in percent tissue coverage for either donor species when compared with each other and with their same species controls. Tissue did not completely regenerate over the surface of the concrete core hole plugs in either species. However, there was no significant difference between the initial area/ radius of the core holes and the final area/ radius for either M. meandrites or M. cavernosa. Additionally, there was no significant difference in the total area change of the core holes when the two species were compared. The results of this study indicated that M. meandrites did not demonstrate statistically significant survivorship or growth as a transplant coral. The M. cavernosa transplants were successful, and displayed a significant increase in surface area. The areas surrounding the core holes did not significantly increase in surface area in either species of donor corals.